1. Field of the Invention
The present invention relates to a method of, and apparatus for, centering an integrated circuit (IC) lead frame. More particularly, the present invention relates to an IC lead frame centering method for positioning ICs connected in series or a single IC, with a lead frame attached thereto, with respect to a center position for fabrication in a manufacturing system, or for positioning ICs of various sizes with respect to a center position on a transfer path to prepare for a subsequent process. The present invention also relates to an apparatus for carrying out the IC lead frame centering method.
2. Description of the Background Art
ICs are manufactured through various fabrication processes. An IC fabrication process in which a lead frame is used is roughly as follows: Upon completion of an IC chip, it is bonded to a lead frame, furnished with wiring, and covered with a plastic material to protect the wiring. Next, unnecessary portions of the lead frame are cut off, and then pin portions are bent into a desired shape by using a bending die, thereby completing an IC. During this fabrication process, the IC may be printed with information, for example, the type of IC, and/or inspected for performance by using an autohandler, if necessary.
Thus, working processes that require a lead frame are roughly divided as follows: processes which are carried out by using a chip holder and a wire bonder, respectively; a plastic molding process; a marking process; a pressing process; and a process which is carried out by using an autohandler. However, since lead frames vary in size from each other, the conventional practice is to center each lead frame by rotating screws so that the lead frame conforms to the apparatus used in each process. Thus, since there are many places where centering must be carried out, it takes a great deal of time.
If centering cannot appropriately be effected, the flow of lead frames becomes unfavorable, causing a large number of defectives to occur. Therefore, no inexperienced operator can be entrusted with the centering operation. Thus, the conventional IC lead frame centering method has been extremely inconvenient and uneconomical.